To provide moldings comprising a polyolefin-based graft copolymer and a polyolefin resin and excellent in radio-frequency welding property.

The polyolefin resin-based composition is prepared by graft copolymerization of an olefinic monomer with a vinyl ester-based macromonomer and adding the obtained to a polyolefin resin, wherein the graft copolymerization is performed in the presence of a coordination polymerization catalyst and the vinyl ester-based macromonomer is produced by emulsion polymerization or microsuspension polymerization. The moldings excellent in radio-frequency welding property are obtained by molding the obtained polyolefin-based resin composition into moldings such as sheets and films.